Direct Synthesis of Boron‐Protected Alkenyl‐ and Alkylborons via Copper‐Catalyzed Formal Hydroboration of Alkynes and Alkenes

Abstract Formal hydroboration of internal alkynes proceeds regio‐ and stereoselectively by the use of a diboron reagent masked with 1,8‐diaminonaphthalene (dan) in the presence of readily available [(Ph3P)3CuCl], leading to direct formation of diverse B‐protected alkenylborons in high yield. The B(dan) moiety can also be efficiently installed into the CC double bond of alkenes to afford the respective alkylborons.